But their polished talons are not a latest fashion trend. Instead, the actors are promoting the Polished Man campaign to end physical and sexual abuse against children.
The campaign follows a similar format to the viral ALS ice bucket challenge, which celebrities nominating others to follow suit.
Efron nominated Hugh Jackman and James Marsden to take part.
“Thanks for the nom, @chrishemsworth. Happy to paint one nail and be a @PolishedMan this month to say no to violence against children. 1 in 5 children are subject to physical and/or sexual violence before the age of 18 and that’s one too many," he wrote in the caption for his picture.
“I nominate the following studs @james_marsden, @thehughjackman, @andybovine, @ders808, @blakeanderson and @deandrejordan6.”Reuse content